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Tim MurphyExtension Weed ScientistUniversity of Georgia

Weed Management Issues for Georgia Cattlemen

PASTWEED.GCA.2012

2Weed competition, how serious is it?Weed competition, how serious is it?

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Rule of thumb: When weeds are more than 20% of the pasture.

What is the Economic Threshold?

Woolly croton

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Do I spray or fertilize first?

Spray first.Control existing

weeds.Begin soil-test

based lime and fertilizer program.

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Grazing for Weed Control Small weeds are more palatable

Many weeds have comparable protein levels to forages

Good fencing and cattle numbers are needed

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Broomsedge is intolerant of early, heavy continuous grazing

Moulton, AL

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“Weeds” in grazing situations serve multiple purposes

Can dilute toxins in tall fescue during critical timesChickweed, crabgrass,

dallisgrass, lespedeza Can extend grazing season

and improve productivityCrabgrass in tall fescue

Can improve qualityCrabgrass and

Johnsongrass

Chickweed, curly dock, shepherds purse and tall fescue mixture. Eatonton GA

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Spray or Bush Spray or Bush Hog?Hog?

About $10/acre including 1 qt/a 2,4-D

About $12 to $14/acre

More than $12/acre

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Mowing

Too late to prevent competition. No selectivity. Perennials will regrow. May prevent weed seed production. Consistency is key to effective weed

control with mowing.

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Mowing

Mowing 3 times per year for 2 years provided 80 to 90% control of ironweed and goldenrod.

12 Late summer mowing of dogfennel provided 80% control

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Herbicides and Legumes

Establish legumes after good weed control has been practiced for 1 to 2 years.

2,4-D amine is safe on white clover and lespedeza.

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Haying and Grazing Restrictions for Dairy Animals (Cattle and Goats)

Lactating Non-lactating

Herbicide Grazing Hay Grazing Hay

Metsulfuron 0 0 0 0

Cimarron Plus 0 0 0 0

Milestone 0 0 0 0

Forefront 0 7 0 7

Chaparral 0 0 0 0

Grazon P+D 7 30 0 30

Remedy One season 14 0 14

Weedmaster 7 37 0 37

2,4-D 7 30 7 30

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Haying and Grazing Restrictions for Various Livestock Species

Beef Horses Goats Beef Horses Goats

Herbicide Grazing Hay

Metsulfuron 0 0 0 0 0 0

Cimarron Plus 0 0 0 0 0 0

Milestone 0 0 0 0 0 0

GrazonNext 0 0 0 7 7 7

Chaparral 0 0 0 0 0 0

Grazon P+D 0 0 0 30 30 30

Remedy 0 0 0 14 14 14

Velpar 0 0 0 38 38 38

Weedmaster 0 0 0 37 37 37

2,4-D 0 0 0 30 30 30

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When do you spray? Winter annuals - henbit, chickweed,

buttercups, thistlesNovember through March

Summer annuals - spiny amaranth, bitter sneezeweedApril through mid-July

Perennialsgrowth stage dependent

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Spray this size Not this size

Bitter sneezeweed

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Herbicide Options1. 2,4-D2. dicamba (Vanquish, Banvel)3. 2,4-D + dicamba (WeedMaster, others)4. dicamba+ diflufenzopyr (Overdrive) 5. diuron (Direx, Diuron) 6. triclopyr (Remedy)7. imazapic (Impose,Panoramic)8. 2,4-D + triclopyr (CrossBow)9. triclopyr + clopyralid (Redeem)10.2,4-D + picloram (Grazon P+D, HiredHand,

GunSlinger)11.fluroxypyr + picloram (Surmount)12.fluroxypyr + triclopyr (PastureGard)13. tebuthiuron (Spike)

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Herbicide Options (cont.)14.aminopyralid (Milestone)15.aminopyralid + 2,4-D (ForeFront, GrazonNext)16.aminopyralid + metsulfuron (Chaparral)17.nicosulfuron + metsulfuron (Pastora)18.metsulfuron (MSM E.Pro, others)19.metsulfuron + chlorsulfuron (Cimarron Plus)20.metsulfuron + 2,4-D + dicamba (Cimarron MAX) 21.hexazinone (Velpar)22.sulfosulfuron (OutRider)23.pendimethalin – Prowl H2O24.paraquat (Gramoxone Inteon, Firestorm, Parazone)25.glyphosate (Roundup PowerMax, others) 26. thifensulfuron + tribenuron (Harmony Extra)27.chlorsulfuron (Telar)

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Newest Herbicides

Milestone – aminopyralid GrazonNext, ForeFront – aminopyralid + 2,4-D Chaparral – aminopyralid + metsulfuron Telar - chlorsulfuron Prowl H2O – pendimethalin

Pastora - nicosulfuron + metsulfuron Harmony Extra - thifensulfuron + tribenuron

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Milestone

2.0 lbs./gal. aminopyralidUse rate: 4.0 to 7.0 fl. ozs./acreNumerous broadleaf weeds – thistles,

horsenettle, tropical soda apple, buttercupDo not seed legumes year of application

(additional research being conducted)Delay application until grasses have 4 to 5

leaves.

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Milestone

Non-volatileInjurious to legumes No grazing or hay restriction for any type

of livestockWeak on sida species, dogfennel,

plantains, blackberry, wild radish, other mustards.

Add 2,4-D or Remedy for weeds above.

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GrazonNext, ForeFront0.33 lbs./gal. aminopyralid + 2.67 lbs./gal 2,4-DUse rate: 1.5 to 2.6 pts./acreNumerous broadleaf weeds – thistles,

horsenettle, buttercup, henbit, plantains, verbena

Do not seed legumes year of application (additional research being conducted)

Delay application until grasses have 4 to 5 leaves.

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Grazon Next, ForeFront

Injurious to legumes No grazing restriction for any type of

livestock.7 day hay harvest restrictionBetter control of plantains and common

pokeweed than Milestone

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Chaparral

Bermuda, orchardgrass, tall fescue (up to 2.0 oz/a

Native grasses – wheatgrass, bluestems, grama

Apply to fully tillered or establishedSame tall fescue precautions as

metsulfuron products (2 yr establishment)

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Chaparral

Rate (oz. product/a)

Act. Ingredient 1.5 2.0* 3.0

aminopyralid 0.049 0.066 0.098

metsulfuron 0.009 0.012 0.018

*Chaparral at 2.0 oz./a = 4.0 fl. oz/a of Milestone 2SC + 0.3 oz/a Metsulfuron 60DG

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Chaparral

Non-volatileInjurious to legumes Do not seed legumes year of application

(additional research being conducted)

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Aminopyralid- It’s Good - BUT!!!!!

Do notuse hay from treated areas for compost or mulchtransfer livestock to untreated areas without

3 d cleanoutuse manure for fertilizing broadleaf cropsuse in any temporary forage system involving

broadleaf crops

USE ONLY ON PERMANENT GRASS FORAGE SYSTEMS

Aminopyralid

For Milestone, ForeFront, Grazon Next, Chaparral:

Aminopyralid is prohibited from use on hay that will be distributed or made available for sale off the farm where harvested unless allowed by supplemental labeling.

Get aminopyralid stewardship info at: http://www.dowagro.com/range/

aminopyralid_stewardship.htm

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Telar Sulfonylurea

Chlorsulfuron 75.0% Bahiagrass, bermudagrass - 0.25 to 1.0 oz/a Tall fescue – 0.25 to 0.5 oz/a

Telar controls: Blackberry, pigweed(s), wild radish Many annual broadleaf weeds < 4.0 in. tall Does not control grass weeds, horsenettle, ragweed, fireweed

(southern nettle) Add nonionic surfactant at 0.25% v/v Highly injurious to legumes No grazing or haying restrictions

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Grass Control Options - Bermudagrass

Dormant bermudaGlyphosate – 1.0 pt./acre (4.0 lb./gal.)Gramoxone Inteon – 1.0 to 2.0 pts./acre

Active Growth Bermuda ‘Pensacola’ bahiagrass – Cimarron, Chaparral,

ImposeSmutgrass – VelparAnnual grasses

Roundup PowerMax, after first hay cut Impose (imazapic)

Johnsongrass – OutRider, Impose Spot treat or ropewick glyphosate

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Prowl H20 - BASF

Pendimethalin Preemergence herbicide: 3.2 to 4.2 qts/acre

Needs rainfall for incorporation within 30 days of application

Labeled on dormant forage bermudagrass hay or pasture (NOT LABELED ON TALL FESCUE)

45 day hay harvest restriction 60 day grazing restriction – all livestock types See supplemental label at: http://www.cdms.net/LDat/ld6CT014.pdf

Pastora – DuPont

Sulfonylurea Nicosulfuron 56.2% + Metsulfuron 15.0%

Pastora controls: Sandbur, panicum sp., foxtails, barnyardgrass, signalgrass < 2.0

in. tall Pensacola bahiagrass, before seedheads emerge in spring Vaseygrass (after hay cutting) Italian ryegrass < 6.0 in. tall Johnsongrass – 6 to 10 in. tall annual broadleaf weeds < 4.0 in. tall

Pastora – DuPont

Use rates: 1.0 to 1.5 oz./acre + NISBermudagrass only (injures tall fescue and

legumes)No grazing or haying restrictionsRotation Intervals

Wheat, ryegrass, fescue – 4 monthsOat, barley – 10 monthsLegumes – 12 months

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Pastora 1.0 oz/a+ COC 1.0% v/v

Pastora 1.0 oz/a+ Roundup PowerMax 11.0 fl. oz/a+ NIS 0.25% v/v

Roundup PowerMax 11.0 fl. oz/a+ NIS 0.25% v/v

Applied Dec. 9, 2010

Applied Feb.14, 2011

Eatonton, GA 2010-2011

Conclusions - Pastora

Will control Italian ryegrassCrabgrass not as sensitive as other annual

grasses (best control of crabgrass is at seedling stage)

Established bermudagrass (one growing season)

Application TimingsWinter – dormant bermudaSpring – before 2 inches of new growthSummer – within 7 days of hay cutting

Harmony Extra Products

Harmony Extra SG – 50 SG0.45 to 0.9 oz/a

Harmony Extra – 75 WDG0.3 to 0.6 oz/a

Both contain thifensulfuron + tribenuronAdd a nonionic surfactant at 0.25% v/v

Harmony Extra Products

Wheat, barley, triticale and oatsApply after two-leaf stage but before flag leaf is visibleControls small henbit, common chickweed, wild radishAlso effective on wild garlicUse at air temps. above 50 F

7 day grazing restriction – all livestock types30 day haying restriction

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Treat at this stage

bull thistle musk thistle

Too late to spray

Thistle Control

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Thistle

Late fall or early spring application

Treat at rosette leaf stage 2,4-D ester WeedMaster Grazon P+D Chaparral ForeFront Milestone Pastora

Musk thistleMusk thistle

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Blackberry

1% Remedy or PastureGard for spray to wet.

2-3 pints per acre for broadcast.

Metsulfuron 0.5 oz per acre. Chaparral, Cimarron

Telar

Spray at full bloom or fall.

Repeat next year may be needed for complete control.

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Blackberry Control

Treatment Rate

% Control

1 year later

PastureGard 1% 87

Remedy 1% 90

Milestone 0.5% 33

June 2005 to June 2006 Faulkner County, AR

43Blackberry control with Remedy, 1 qt/ac, Fall application, 6 MAT

44Blackberry control with Cimarron Plus 0.5 ozs/ac at bloom – 5 MAT

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Dewberry

0.625 oz Cimarron Plus per acre.

Spray at full bloom.

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Dewberry

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Dogfennel Perennial – seed,

roots

Treat at 18 to 24 inch growth stage

Best – PastureGard, Remedy, Grazon P+D, Weedmaster

Good – 2,4-D, 2.0 qts./acre

Poor to Fair –Metsulfuron

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Hemp Dogbane Very tough to control. Surmount at 3 to 6 pts

per acre is the best. Remedy provides

temporary burn down.

Milky juice

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Horsenettle

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Best – Grazon P+D at 3.0 pts./acre or ForeFront at 2.6 pts/ac

Fair – WeedMaster at 4.0 pt./acre or 2,4-D at 3 pts/ac

Add a nonionic surfactant at 0.25% v/v.

Apply at mid-bloom through fruiting

Horsenettle

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Spiny amaranth

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Treat when small (2 to 4 inches) early May

Metsulfuron 0.25 to 0.33 oz/acre

Grazon P+D, Weedmaster, 2,4-D - 1-2 pts/acre, Cimarron Max 1 pt + 0.25 oz

Germinates all summer. Repeat applications needed.

Pigweed

Pigweed seed

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Identify weedIdentify weedSelect the right productSelect the right productTime the application correctlyTime the application correctlyApply accuratelyApply accuratelyFollow grazing and haying restrictionsFollow grazing and haying restrictions

Keys to Herbicide Use

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Incorporate…MowingGrazing FertilizationHerbicides

……in an integrated approach to weed management